In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

"You have a pattern of behaviour here where the prime minister likes to go out on the razzle-dazzle announcements, the good news stories, but when there's actually anything difficult to be done or anything difficult to be said on behalf of the government, he's nowhere," she told the ABC on Wednesday.

She said she'd been assured the woman who made the complaint regarding Mr Briggs had not been penalised for raising the issue.

Mr Turnbull said the timing of the announcements was made following due process.

"The announcement about Mr Briggs was made on the first business day after Christmas," he said.

Although he refused to describe the Hong Kong incident in detail, Mr Turnbull said it was a serious matter and "did not live up to the standard required of ministers".

Mr Brough was advised by his lawyers the investigations into his conduct were unlikely to be completed before parliament resumed in February, Mr Turnbull said.

"It's a political decision but of course he hasn't been charged with anything, let alone found guilty of anything, so it's essentially a political judgment," he said.

The timing of both announcements was "perfectly appropriate", Mr Turnbull said.